1
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Rodríguez‐Molina JB, Turtola M. Birth of a poly(A) tail: mechanisms and control of mRNA polyadenylation. FEBS Open Bio 2023; 13:1140-1153. [PMID: 36416579 PMCID: PMC10315857 DOI: 10.1002/2211-5463.13528] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/17/2022] [Accepted: 11/22/2022] [Indexed: 11/24/2022] Open
Abstract
During their synthesis in the cell nucleus, most eukaryotic mRNAs undergo a two-step 3'-end processing reaction in which the pre-mRNA is cleaved and released from the transcribing RNA polymerase II and a polyadenosine (poly(A)) tail is added to the newly formed 3'-end. These biochemical reactions might appear simple at first sight (endonucleolytic RNA cleavage and synthesis of a homopolymeric tail), but their catalysis requires a multi-faceted enzymatic machinery, the cleavage and polyadenylation complex (CPAC), which is composed of more than 20 individual protein subunits. The activity of CPAC is further orchestrated by Poly(A) Binding Proteins (PABPs), which decorate the poly(A) tail during its synthesis and guide the mRNA through subsequent gene expression steps. Here, we review the structure, molecular mechanism, and regulation of eukaryotic mRNA 3'-end processing machineries with a focus on the polyadenylation step. We concentrate on the CPAC and PABPs from mammals and the budding yeast, Saccharomyces cerevisiae, because these systems are the best-characterized at present. Comparison of their functions provides valuable insights into the principles of mRNA 3'-end processing.
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Affiliation(s)
| | - Matti Turtola
- Department of Life TechnologiesUniversity of TurkuFinland
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2
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Arfelli VC, Chang YC, Bagnoli JW, Kerbs P, Ciamponi FE, Paz LMDS, Pankivskyi S, de Matha Salone J, Maucuer A, Massirer KB, Enard W, Kuster B, Greif PA, Archangelo LF. UHMK1 is a novel splicing regulatory kinase. J Biol Chem 2023; 299:103041. [PMID: 36803961 PMCID: PMC10033318 DOI: 10.1016/j.jbc.2023.103041] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/18/2023] [Accepted: 02/04/2023] [Indexed: 02/19/2023] Open
Abstract
The U2AF Homology Motif Kinase 1 (UHMK1) is the only kinase that contains the U2AF homology motif, a common protein interaction domain among splicing factors. Through this motif, UHMK1 interacts with the splicing factors SF1 and SF3B1, known to participate in the 3' splice site recognition during the early steps of spliceosome assembly. Although UHMK1 phosphorylates these splicing factors in vitro, the involvement of UHMK1 in RNA processing has not previously been demonstrated. Here, we identify novel putative substrates of this kinase and evaluate UHMK1 contribution to overall gene expression and splicing, by integrating global phosphoproteomics, RNA-seq, and bioinformatics approaches. Upon UHMK1 modulation, 163 unique phosphosites were differentially phosphorylated in 117 proteins, of which 106 are novel potential substrates of this kinase. Gene Ontology analysis showed enrichment of terms previously associated with UHMK1 function, such as mRNA splicing, cell cycle, cell division, and microtubule organization. The majority of the annotated RNA-related proteins are components of the spliceosome but are also involved in several steps of gene expression. Comprehensive analysis of splicing showed that UHMK1 affected over 270 alternative splicing events. Moreover, splicing reporter assay further supported UHMK1 function on splicing. Overall, RNA-seq data demonstrated that UHMK1 knockdown had a minor impact on transcript expression and pointed to UHMK1 function in epithelial-mesenchymal transition. Functional assays demonstrated that UHMK1 modulation affects proliferation, colony formation, and migration. Taken together, our data implicate UHMK1 as a splicing regulatory kinase, connecting protein regulation through phosphorylation and gene expression in key cellular processes.
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Affiliation(s)
- Vanessa C Arfelli
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil
| | - Yun-Chien Chang
- Proteomics and Bioanalytics, School of Life Sciences Weihenstephan, Technical University of Munich (TUM), Freising, Germany
| | - Johannes W Bagnoli
- Anthropology & Human Genomics, Department of Biology II, Ludwig-Maximilians-University (LMU), Martinsried, Germany
| | - Paul Kerbs
- Laboratory for Experimental Leukemia and Lymphoma Research, Munich University Hospital, Ludwig-Maximilians University (LMU), Munich, Germany; German Cancer Consortium (DKTK), partner site Munich, Munich, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Felipe E Ciamponi
- Center for Medicinal Chemistry (CQMED), Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Laissa M da S Paz
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil
| | - Serhii Pankivskyi
- SABNP, Univ Evry, INSERM U1204, Université Paris-Saclay, Evry, France
| | | | - Alexandre Maucuer
- SABNP, Univ Evry, INSERM U1204, Université Paris-Saclay, Evry, France
| | - Katlin B Massirer
- Center for Medicinal Chemistry (CQMED), Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Wolfgang Enard
- Anthropology & Human Genomics, Department of Biology II, Ludwig-Maximilians-University (LMU), Martinsried, Germany
| | - Bernhard Kuster
- Proteomics and Bioanalytics, School of Life Sciences Weihenstephan, Technical University of Munich (TUM), Freising, Germany
| | - Philipp A Greif
- Laboratory for Experimental Leukemia and Lymphoma Research, Munich University Hospital, Ludwig-Maximilians University (LMU), Munich, Germany; German Cancer Consortium (DKTK), partner site Munich, Munich, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Leticia Fröhlich Archangelo
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.
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3
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Ospina-Villa JD, Tovar-Ayona BJ, López-Camarillo C, Soto-Sánchez J, Ramírez-Moreno E, Castañón-Sánchez CA, Marchat LA. mRNA Polyadenylation Machineries in Intestinal Protozoan Parasites. J Eukaryot Microbiol 2020; 67:306-320. [PMID: 31898347 DOI: 10.1111/jeu.12781] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 12/16/2019] [Accepted: 12/22/2019] [Indexed: 12/22/2022]
Abstract
In humans, mRNA polyadenylation involves the participation of about 20 factors in four main complexes that recognize specific RNA sequences. Notably, CFIm25, CPSF73, and PAP have essential roles for poly(A) site selection, mRNA cleavage, and adenosine residues polymerization. Besides the relevance of polyadenylation for gene expression, information is scarce in intestinal protozoan parasites that threaten human health. To better understand polyadenylation in Entamoeba histolytica, Giardia lamblia, and Cryptosporidium parvum, which represent leading causes of diarrhea worldwide, genomes were screened for orthologs of human factors. Results showed that Entamoeba histolytica and C. parvum have 16 and 12 proteins out of the 19 human proteins used as queries, respectively, while G. lamblia seems to have the smallest polyadenylation machinery with only six factors. Remarkably, CPSF30, CPSF73, CstF77, PABP2, and PAP, which were found in all parasites, could represent the core polyadenylation machinery. Multiple genes were detected for several proteins in Entamoeba, while gene redundancy is lower in Giardia and Cryptosporidium. Congruently with their relevance in the polyadenylation process, CPSF73 and PAP are present in all parasites, and CFIm25 is only missing in Giardia. They conserve the functional domains and predicted folding of human proteins, suggesting they may have the same roles in polyadenylation.
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Affiliation(s)
- Juan David Ospina-Villa
- Independent Researcher, Transversal 27A Sur # 42-14, C.P. 055421, Envigado, Antioquia, Colombia
| | - Brisna Joana Tovar-Ayona
- Posgrados en Biomedicina Molecular y en Biotecnología, ENMH, Instituto Politécnico Nacional, Av. Guillermo Massieu Helguera 239, Col. La Escalera, Gustavo A. Madero, C.P. 07320, Ciudad de México, Mexico
| | - César López-Camarillo
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo 290, Col. del Valle Sur, Benito Juárez, C.P. 03100, Ciudad de México, Mexico
| | - Jacqueline Soto-Sánchez
- Posgrados en Biomedicina Molecular y en Biotecnología, ENMH, Instituto Politécnico Nacional, Av. Guillermo Massieu Helguera 239, Col. La Escalera, Gustavo A. Madero, C.P. 07320, Ciudad de México, Mexico
| | - Esther Ramírez-Moreno
- Posgrados en Biomedicina Molecular y en Biotecnología, ENMH, Instituto Politécnico Nacional, Av. Guillermo Massieu Helguera 239, Col. La Escalera, Gustavo A. Madero, C.P. 07320, Ciudad de México, Mexico
| | - Carlos A Castañón-Sánchez
- Hospital Regional de Alta Especialidad de Oaxaca, Aldama s/n, Col. Centro, C.P. 71256 San Bartolo Coyotepec, Oaxaca, Mexico
| | - Laurence A Marchat
- Posgrados en Biomedicina Molecular y en Biotecnología, ENMH, Instituto Politécnico Nacional, Av. Guillermo Massieu Helguera 239, Col. La Escalera, Gustavo A. Madero, C.P. 07320, Ciudad de México, Mexico
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4
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Wegener M, Müller-McNicoll M. Nuclear retention of mRNAs - quality control, gene regulation and human disease. Semin Cell Dev Biol 2017; 79:131-142. [PMID: 29102717 DOI: 10.1016/j.semcdb.2017.11.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/30/2017] [Accepted: 11/01/2017] [Indexed: 12/21/2022]
Abstract
Nuclear retention of incompletely spliced or mature mRNAs emerges as a novel, previously underappreciated layer of gene regulation, which enables the cell to rapidly respond to stress, viral infection, differentiation cues or changing environmental conditions. Focusing on mammalian cells, we discuss recent insights into the mechanisms and functions of nuclear retention, describe retention-promoting features in protein-coding transcripts and propose mechanisms for their regulated release into the cytoplasm. Moreover, we discuss examples of how aberrant nuclear retention of mRNAs may lead to human diseases.
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Affiliation(s)
- Marius Wegener
- RNA Regulation Group, Cluster of Excellence 'Macromolecular Complexes', Goethe University Frankfurt, Institute of Cell Biology and Neuroscience, Max-von-Laue-Str. 13, 60438 Frankfurt/Main, Germany
| | - Michaela Müller-McNicoll
- RNA Regulation Group, Cluster of Excellence 'Macromolecular Complexes', Goethe University Frankfurt, Institute of Cell Biology and Neuroscience, Max-von-Laue-Str. 13, 60438 Frankfurt/Main, Germany.
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5
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Neve J, Patel R, Wang Z, Louey A, Furger AM. Cleavage and polyadenylation: Ending the message expands gene regulation. RNA Biol 2017; 14:865-890. [PMID: 28453393 PMCID: PMC5546720 DOI: 10.1080/15476286.2017.1306171] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/02/2017] [Accepted: 03/09/2017] [Indexed: 12/13/2022] Open
Abstract
Cleavage and polyadenylation (pA) is a fundamental step that is required for the maturation of primary protein encoding transcripts into functional mRNAs that can be exported from the nucleus and translated in the cytoplasm. 3'end processing is dependent on the assembly of a multiprotein processing complex on the pA signals that reside in the pre-mRNAs. Most eukaryotic genes have multiple pA signals, resulting in alternative cleavage and polyadenylation (APA), a widespread phenomenon that is important to establish cell state and cell type specific transcriptomes. Here, we review how pA sites are recognized and comprehensively summarize how APA is regulated and creates mRNA isoform profiles that are characteristic for cell types, tissues, cellular states and disease.
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Affiliation(s)
- Jonathan Neve
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Radhika Patel
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Zhiqiao Wang
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Alastair Louey
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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6
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Hanley ML, Yoo TY, Sonnett M, Needleman DJ, Mitchison TJ. Chromosomal passenger complex hydrodynamics suggests chaperoning of the inactive state by nucleoplasmin/nucleophosmin. Mol Biol Cell 2017; 28:1444-1456. [PMID: 28404751 PMCID: PMC5449145 DOI: 10.1091/mbc.e16-12-0860] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/27/2017] [Accepted: 04/04/2017] [Indexed: 01/30/2023] Open
Abstract
The chromosomal passenger complex (CPC) is a conserved, essential regulator of cell division. As such, significant anti-cancer drug development efforts have been focused on targeting it, most notably by inhibiting its AURKB kinase subunit. The CPC is activated by AURKB-catalyzed autophosphorylation on multiple subunits, but how this regulates CPC interactions with other mitotic proteins remains unclear. We investigated the hydrodynamic behavior of the CPC in Xenopus laevis egg cytosol using sucrose gradient sedimentation and in HeLa cells using fluorescence correlation spectroscopy. We found that autophosphorylation of the CPC decreases its sedimentation coefficient in egg cytosol and increases its diffusion coefficient in live cells, indicating a decrease in mass. Using immunoprecipitation coupled with mass spectrometry and immunoblots, we discovered that inactive, unphosphorylated CPC interacts with nucleophosmin/nucleoplasmin proteins, which are known to oligomerize into pentamers and decamers. Autophosphorylation of the CPC causes it to dissociate from nucleophosmin/nucleoplasmin. We propose that nucleophosmin/nucleoplasmin complexes serve as chaperones that negatively regulate the CPC and/or stabilize its inactive form, preventing CPC autophosphorylation and recruitment to chromatin and microtubules in mitosis.
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Affiliation(s)
- Mariah L Hanley
- Department of Systems Biology, Harvard Medical School, Boston, MA 02114-5701.,Department of Chemistry, Harvard University, Cambridge, MA 02138-2902
| | - Tae Yeon Yoo
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138-2902
| | - Matthew Sonnett
- Department of Systems Biology, Harvard Medical School, Boston, MA 02114-5701
| | - Daniel J Needleman
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138-2902.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138-2902
| | - Timothy J Mitchison
- Department of Systems Biology, Harvard Medical School, Boston, MA 02114-5701
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7
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Björk P, Wieslander L. Integration of mRNP formation and export. Cell Mol Life Sci 2017; 74:2875-2897. [PMID: 28314893 PMCID: PMC5501912 DOI: 10.1007/s00018-017-2503-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 12/13/2022]
Abstract
Expression of protein-coding genes in eukaryotes relies on the coordinated action of many sophisticated molecular machineries. Transcription produces precursor mRNAs (pre-mRNAs) and the active gene provides an environment in which the pre-mRNAs are processed, folded, and assembled into RNA–protein (RNP) complexes. The dynamic pre-mRNPs incorporate the growing transcript, proteins, and the processing machineries, as well as the specific protein marks left after processing that are essential for export and the cytoplasmic fate of the mRNPs. After release from the gene, the mRNPs move by diffusion within the interchromatin compartment, making up pools of mRNPs. Here, splicing and polyadenylation can be completed and the mRNPs recruit the major export receptor NXF1. Export competent mRNPs interact with the nuclear pore complex, leading to export, concomitant with compositional and conformational changes of the mRNPs. We summarize the integrated nuclear processes involved in the formation and export of mRNPs.
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Affiliation(s)
- Petra Björk
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Lars Wieslander
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
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8
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Roviello GN, Musumeci D, Roviello V, Pirtskhalava M, Egoyan A, Mirtskhulava M. Natural and artificial binders of polyriboadenylic acid and their effect on RNA structure. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2015; 6:1338-1347. [PMID: 26199837 PMCID: PMC4505092 DOI: 10.3762/bjnano.6.138] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 05/22/2015] [Indexed: 06/10/2023]
Abstract
The employment of molecular tools with nucleic acid binding ability to specifically control crucial cellular functions represents an important scientific area at the border between biochemistry and pharmaceutical chemistry. In this review we describe several molecular systems of natural or artificial origin, which are able to bind polyriboadenylic acid (poly(rA)) both in its single-stranded or structured forms. Due to the fundamental role played by the poly(rA) tail in the maturation and stability of mRNA, as well as in the initiation of the translation process, compounds able to bind this RNA tract, influencing the mRNA fate, are of special interest for developing innovative biomedical strategies mainly in the field of anticancer therapy.
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Affiliation(s)
- Giovanni N Roviello
- Istituto di Biostrutture e Bioimmagini - CNR, via Mezzocannone 16, 80134 Napoli, Italy
| | - Domenica Musumeci
- Istituto di Biostrutture e Bioimmagini - CNR, via Mezzocannone 16, 80134 Napoli, Italy
- Dipartimento di Scienze Chimiche, Università di Napoli “Federico II”, 80126 Napoli, Italy
| | - Valentina Roviello
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale (DICMaPI), Università di Napoli “Federico II”, 80125 Napoli, Italy
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9
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Singh G, Pratt G, Yeo GW, Moore MJ. The Clothes Make the mRNA: Past and Present Trends in mRNP Fashion. Annu Rev Biochem 2015; 84:325-54. [PMID: 25784054 DOI: 10.1146/annurev-biochem-080111-092106] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Throughout their lifetimes, messenger RNAs (mRNAs) associate with proteins to form ribonucleoproteins (mRNPs). Since the discovery of the first mRNP component more than 40 years ago, what is known as the mRNA interactome now comprises >1,000 proteins. These proteins bind mRNAs in myriad ways with varying affinities and stoichiometries, with many assembling onto nascent RNAs in a highly ordered process during transcription and precursor mRNA (pre-mRNA) processing. The nonrandom distribution of major mRNP proteins observed in transcriptome-wide studies leads us to propose that mRNPs are organized into three major domains loosely corresponding to 5' untranslated regions (UTRs), open reading frames, and 3' UTRs. Moving from the nucleus to the cytoplasm, mRNPs undergo extensive remodeling as they are first acted upon by the nuclear pore complex and then by the ribosome. When not being actively translated, cytoplasmic mRNPs can assemble into large multi-mRNP assemblies or be permanently disassembled and degraded. In this review, we aim to give the reader a thorough understanding of past and current eukaryotic mRNP research.
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Affiliation(s)
- Guramrit Singh
- Department of Molecular Genetics, Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210;
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10
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Dong C, Vashisht A, Hegde AN. Proteasome regulates the mediators of cytoplasmic polyadenylation signaling during late-phase long-term potentiation. Neurosci Lett 2014; 583:199-204. [PMID: 25263789 DOI: 10.1016/j.neulet.2014.09.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/30/2014] [Accepted: 09/17/2014] [Indexed: 11/29/2022]
Abstract
The ubiquitin-proteasome pathway is essential for long-term synaptic plasticity, but its exact roles remain unclear. Previously we established that proteasome inhibition increased the early, induction part of late-phase long-term potentiation (L-LTP) but blocks the late, maintenance part. Our prior work also showed that the proteasome modulates components of the mammalian target of rapamycin pathway for translation. In this study, we tested the possible role of the proteasome in regulating the cytoplasmic polyadenylation signaling required for translation during L-LTP. We found that a polyadenylation inhibitor cordycepin diminishes the enhancement of early L-LTP mediated by proteasome inhibition. Furthermore, blocking Aurora-A kinase and calcium-calmodulin-dependent kinase II reduces the increase in early L-LTP brought about by proteasome inhibition. Our results suggest a link between polyadenylation-mediated translational control and protein degradation during induction of long-term synaptic plasticity.
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Affiliation(s)
- Chenghai Dong
- Department of Neurobiology and Anatomy, Wake Forest University Health Sciences Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Anirudh Vashisht
- Department of Neurobiology and Anatomy, Wake Forest University Health Sciences Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Ashok N Hegde
- Department of Neurobiology and Anatomy, Wake Forest University Health Sciences Medical Center Boulevard, Winston-Salem, NC 27157, USA.
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11
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Laishram RS. Poly(A) polymerase (PAP) diversity in gene expression--star-PAP vs canonical PAP. FEBS Lett 2014; 588:2185-97. [PMID: 24873880 PMCID: PMC6309179 DOI: 10.1016/j.febslet.2014.05.029] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 05/02/2014] [Accepted: 05/15/2014] [Indexed: 01/09/2023]
Abstract
Almost all eukaryotic mRNAs acquire a poly(A) tail at the 3'-end by a concerted RNA processing event: cleavage and polyadenylation. The canonical PAP, PAPα, was considered the only nuclear PAP involved in general polyadenylation of mRNAs. A phosphoinositide-modulated nuclear PAP, Star-PAP, was then reported to regulate a select set of mRNAs in the cell. In addition, several non-canonical PAPs have been identified with diverse cellular functions. Further, canonical PAP itself exists in multiple isoforms thus illustrating the diversity of PAPs. In this review, we compare two nuclear PAPs, Star-PAP and PAPα with a general overview of PAP diversity in the cell. Emerging evidence suggests distinct niches of target pre-mRNAs for the two PAPs and that modulation of these PAPs regulates distinct cellular functions.
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Affiliation(s)
- Rakesh S Laishram
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.
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12
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Jalkanen AL, Coleman SJ, Wilusz J. Determinants and implications of mRNA poly(A) tail size--does this protein make my tail look big? Semin Cell Dev Biol 2014; 34:24-32. [PMID: 24910447 DOI: 10.1016/j.semcdb.2014.05.018] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 05/31/2014] [Indexed: 12/22/2022]
Abstract
While the phenomenon of polyadenylation has been well-studied, the dynamics of poly(A) tail size and its impact on transcript function and cell biology are less well-appreciated. The goal of this review is to encourage readers to view the poly(A) tail as a dynamic, changeable aspect of a transcript rather than a simple static entity that marks the 3' end of an mRNA. This could open up new angles of regulation in the post-transcriptional control of gene expression throughout development, differentiation and cancer.
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Affiliation(s)
- Aimee L Jalkanen
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Stephen J Coleman
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
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13
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Martinelli C, Colombo E, Piccini D, Sironi C, Pelicci PG, de Marco A. An intrabody specific for the nucleophosmin carboxy-terminal mutant and fused to a nuclear localization sequence binds its antigen but fails to relocate it in the nucleus. ACTA ACUST UNITED AC 2014. [PMID: 28626645 PMCID: PMC5466097 DOI: 10.1016/j.btre.2014.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A scFv intrabody specific for the NPMc+ mutant NES sequence was isolated. It was expressed as a fusion with a NLS and such construct accumulates in the nucleus. The scFv-NLS fusion binds its antigen in the cytoplasm of eukaryotic cells. The complex shuttles to the nucleus but accumulates in the cytoplasm. Stronger NLS should be developed to revert the strength of pathogenic NES.
The cytoplasmic accumulation of NPM1 (NPMc+) is found in acute myeloid leukemia (AML) with NPM1 mutation. NPM1 must shuttle between nucleus and cytoplasm to assure physiological protein synthesis and, therefore, the elimination of NPMc+ is not a suitable therapeutic option. We isolated, characterized, and produced a functional scFv intrabody fused to nuclear localization signal(s) (NLS) that does not recognize NPM1 but binds to the mutant-specific C-terminal NES (nuclear export signal) of NPMc+, responsible for its cytoplasmic accumulation. The scFv-NLS fusion accumulated in the nuclei of wild type cells and strongly bound to its antigen in the cytoplasm of NPMc+ expressing cells. However, it failed to relocate the majority of NPMc+ in the nucleus, even when fused to four NLS. Our results show the technical feasibility of producing recombinant intrabodies with defined sub-cellular targeting and nuclear accumulation but the lack of information concerning the features that confer variable strength to the signal peptides impairs the development of biomolecules able to counteract pathological sub-cellular distribution of shuttling proteins.
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Affiliation(s)
| | - Emanuela Colombo
- Department of Experimental Oncology, IEO, Via Adamello 16, 20139 Milan, Italy.,Department of Health Sciences, University of Milan, 20133 Milan, Italy
| | | | - Cristina Sironi
- Department of Experimental Oncology, IEO, Via Adamello 16, 20139 Milan, Italy
| | - Pier Giuseppe Pelicci
- Department of Experimental Oncology, IEO, Via Adamello 16, 20139 Milan, Italy.,Department of Health Sciences, University of Milan, 20133 Milan, Italy
| | - Ario de Marco
- Department of Biomedical Sciences and Engineering, University of Nova Gorica, Glavni Trg 9, SI-5261 Vipava, Slovenia
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14
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Yan YB. Deadenylation: enzymes, regulation, and functional implications. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:421-43. [PMID: 24523229 DOI: 10.1002/wrna.1221] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 12/20/2013] [Accepted: 12/21/2013] [Indexed: 12/27/2022]
Abstract
Lengths of the eukaryotic messenger RNA (mRNA) poly(A) tails are dynamically changed by the opposing effects of poly(A) polymerases and deadenylases. Modulating poly(A) tail length provides a highly regulated means to control almost every stage of mRNA lifecycle including transcription, processing, quality control, transport, translation, silence, and decay. The existence of diverse deadenylases with distinct properties highlights the importance of regulating poly(A) tail length in cellular functions. The deadenylation activity can be modulated by subcellular locations of the deadenylases, cis-acting elements in the target mRNAs, trans-acting RNA-binding proteins, posttranslational modifications of deadenylase and associated factors, as well as transcriptional and posttranscriptional regulation of the deadenylase genes. Among these regulators, the physiological functions of deadenylases are largely dependent on the interactions with the trans-acting RNA-binding proteins, which recruit deadenylases to the target mRNAs. The task of these RNA-binding proteins is to find and mark the target mRNAs based on their sequence features. Regulation of the regulators can switch on or switch off deadenylation and thereby destabilize or stabilize the targeted mRNAs, respectively. The distinct domain compositions and cofactors provide various deadenylases the structural basis for the recruitments by distinct RNA-binding protein subsets to meet dissimilar cellular demands. The diverse deadenylases, the numerous types of regulators, and the reversible posttranslational modifications together make up a complicated network to precisely regulate intracellular mRNA homeostasis. This review will focus on the diverse regulators of various deadenylases and will discuss their functional implications, remaining problems, and future challenges.
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Affiliation(s)
- Yong-Bin Yan
- State Key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, Beijing, China
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Charlesworth A, Meijer HA, de Moor CH. Specificity factors in cytoplasmic polyadenylation. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 4:437-61. [PMID: 23776146 PMCID: PMC3736149 DOI: 10.1002/wrna.1171] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 04/08/2013] [Accepted: 04/09/2013] [Indexed: 12/12/2022]
Abstract
Poly(A) tail elongation after export of an messenger RNA (mRNA) to the cytoplasm is called cytoplasmic polyadenylation. It was first discovered in oocytes and embryos, where it has roles in meiosis and development. In recent years, however, has been implicated in many other processes, including synaptic plasticity and mitosis. This review aims to introduce cytoplasmic polyadenylation with an emphasis on the factors and elements mediating this process for different mRNAs and in different animal species. We will discuss the RNA sequence elements mediating cytoplasmic polyadenylation in the 3' untranslated regions of mRNAs, including the CPE, MBE, TCS, eCPE, and C-CPE. In addition to describing the role of general polyadenylation factors, we discuss the specific RNA binding protein families associated with cytoplasmic polyadenylation elements, including CPEB (CPEB1, CPEB2, CPEB3, and CPEB4), Pumilio (PUM2), Musashi (MSI1, MSI2), zygote arrest (ZAR2), ELAV like proteins (ELAVL1, HuR), poly(C) binding proteins (PCBP2, αCP2, hnRNP-E2), and Bicaudal C (BICC1). Some emerging themes in cytoplasmic polyadenylation will be highlighted. To facilitate understanding for those working in different organisms and fields, particularly those who are analyzing high throughput data, HUGO gene nomenclature for the human orthologs is used throughout. Where human orthologs have not been clearly identified, reference is made to protein families identified in man.
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Affiliation(s)
- Amanda Charlesworth
- Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA
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The human nuclear poly(a)-binding protein promotes RNA hyperadenylation and decay. PLoS Genet 2013; 9:e1003893. [PMID: 24146636 PMCID: PMC3798265 DOI: 10.1371/journal.pgen.1003893] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 09/05/2013] [Indexed: 12/05/2022] Open
Abstract
Control of nuclear RNA stability is essential for proper gene expression, but the mechanisms governing RNA degradation in mammalian nuclei are poorly defined. In this study, we uncover a mammalian RNA decay pathway that depends on the nuclear poly(A)-binding protein (PABPN1), the poly(A) polymerases (PAPs), PAPα and PAPγ, and the exosome subunits RRP6 and DIS3. Using a targeted knockdown approach and nuclear RNA reporters, we show that PABPN1 and PAPα, redundantly with PAPγ, generate hyperadenylated decay substrates that are recognized by the exosome and degraded. Poly(A) tail extension appears to be necessary for decay, as cordycepin treatment or point mutations in the PAP-stimulating domain of PABPN1 leads to the accumulation of stable transcripts with shorter poly(A) tails than controls. Mechanistically, these data suggest that PABPN1-dependent promotion of PAP activity can stimulate nuclear RNA decay. Importantly, efficiently exported RNAs are unaffected by this decay pathway, supporting an mRNA quality control function for this pathway. Finally, analyses of both bulk poly(A) tails and specific endogenous transcripts reveals that a subset of nuclear RNAs are hyperadenylated in a PABPN1-dependent fashion, and this hyperadenylation can be either uncoupled or coupled with decay. Our results highlight a complex relationship between PABPN1, PAPα/γ, and nuclear RNA decay, and we suggest that these activities may play broader roles in the regulation of human gene expression. In eukaryotes, mRNAs include a stretch of adenosine nucleotides at their 3′ end termed the poly(A) tail. In the cytoplasm, the poly(A) tail stimulates translation of the mRNA into protein, and protects the transcript from degradation. Evidence suggests that poly(A) tails may play distinct roles in RNA metabolism in the nucleus, but little is known about these functions and mechanisms. We show here that poly(A) tails can stimulate transcript decay in the nucleus, a function mediated by the ubiquitous nuclear poly(A) binding protein PABPN1. We find that PABPN1 is required for the degradation of a viral nuclear noncoding RNA as well as an inefficiently exported human mRNA. Importantly, the targeting of RNAs to this decay pathway requires the PABPN1 and poly(A) polymerase-dependent extension of the poly(A) tail. Nuclear transcripts with longer poly(A) tails are then selectively degraded by components of the nuclear exosome. These studies elucidate mechanisms that mammalian cells use to ensure proper mRNA “quality control” and may be important to regulate the expression of nuclear noncoding RNAs. Furthermore, our results suggest that the poly(A) tail has diverse and context-specific roles in gene expression.
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αCP Poly(C) binding proteins act as global regulators of alternative polyadenylation. Mol Cell Biol 2013; 33:2560-73. [PMID: 23629627 DOI: 10.1128/mcb.01380-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We have previously demonstrated that the KH-domain protein αCP binds to a 3' untranslated region (3'UTR) C-rich motif of the nascent human alpha-globin (hα-globin) transcript and enhances the efficiency of 3' processing. Here we assess the genome-wide impact of αCP RNA-protein (RNP) complexes on 3' processing with a specific focus on its role in alternative polyadenylation (APA) site utilization. The major isoforms of αCP were acutely depleted from a human hematopoietic cell line, and the impact on mRNA representation and poly(A) site utilization was determined by direct RNA sequencing (DRS). Bioinformatic analysis revealed 357 significant alterations in poly(A) site utilization that could be specifically linked to the αCP depletion. These APA events correlated strongly with the presence of C-rich sequences in close proximity to the impacted poly(A) addition sites. The most significant linkage was the presence of a C-rich motif within a window 30 to 40 bases 5' to poly(A) signals (AAUAAA) that were repressed upon αCP depletion. This linkage is consistent with a general role for αCPs as enhancers of 3' processing. These findings predict a role for αCPs in posttranscriptional control pathways that can alter the coding potential and/or levels of expression of subsets of mRNAs in the mammalian transcriptome.
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Yamashita A. Role of SMG-1-mediated Upf1 phosphorylation in mammalian nonsense-mediated mRNA decay. Genes Cells 2013; 18:161-75. [DOI: 10.1111/gtc.12033] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Accepted: 12/06/2012] [Indexed: 12/14/2022]
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Godwin AR, Kojima S, Green CB, Wilusz J. Kiss your tail goodbye: the role of PARN, Nocturnin, and Angel deadenylases in mRNA biology. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1829:571-9. [PMID: 23274303 DOI: 10.1016/j.bbagrm.2012.12.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Revised: 12/12/2012] [Accepted: 12/16/2012] [Indexed: 01/06/2023]
Abstract
PARN, Nocturnin and Angel are three of the multiple deadenylases that have been described in eukaryotic cells. While each of these enzymes appear to target poly(A) tails for shortening and influence RNA gene expression levels and quality control, the enzymes differ in terms of enzymatic mechanisms, regulation and biological impact. The goal of this review is to provide an in depth biochemical and biological perspective of the PARN, Nocturnin and Angel deadenylases. Understanding the shared and unique roles of these enzymes in cell biology will provide important insights into numerous aspects of the post-transcriptional control of gene expression. This article is part of a Special Issue entitled: RNA Decay mechanisms.
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Affiliation(s)
- Alan R Godwin
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
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Kondrashov A, Meijer HA, Barthet-Barateig A, Parker HN, Khurshid A, Tessier S, Sicard M, Knox AJ, Pang L, de Moor CH. Inhibition of polyadenylation reduces inflammatory gene induction. RNA (NEW YORK, N.Y.) 2012; 18:2236-2250. [PMID: 23118416 PMCID: PMC3504674 DOI: 10.1261/rna.032391.112] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 09/14/2012] [Indexed: 05/31/2023]
Abstract
Cordycepin (3' deoxyadenosine) has long been used in the study of in vitro assembled polyadenylation complexes, because it terminates the poly(A) tail and arrests the cleavage complex. It is derived from caterpillar fungi, which are highly prized in Chinese traditional medicine. Here we show that cordycepin specifically inhibits the induction of inflammatory mRNAs by cytokines in human airway smooth muscle cells without affecting the expression of control mRNAs. Cordycepin treatment results in shorter poly(A) tails, and a reduction in the efficiency of mRNA cleavage and transcription termination is observed, indicating that the effects of cordycepin on 3' processing in cells are similar to those described in in vitro reactions. For the CCL2 and CXCL1 mRNAs, the effects of cordycepin are post-transcriptional, with the mRNA disappearing during or immediately after nuclear export. In contrast, although the recruitment of RNA polymerase II to the IL8 promoter is also unaffected, the levels of nascent transcript are reduced, indicating a defect in transcription elongation. We show that a reporter construct with 3' sequences from a histone gene is unaffected by cordycepin, while CXCL1 sequences confer cordycepin sensitivity to the reporter, demonstrating that polyadenylation is indeed required for the effect of cordycepin on gene expression. In addition, treatment with another polyadenyation inhibitor and knockdown of poly(A) polymerase α also specifically reduced the induction of inflammatory mRNAs. These data demonstrate that there are differences in the 3' processing of inflammatory and housekeeping genes and identify polyadenylation as a novel target for anti-inflammatory drugs.
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Affiliation(s)
- Alexander Kondrashov
- School of Pharmacy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Hedda A. Meijer
- School of Clinical Sciences, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | | | - Hannah N. Parker
- School of Pharmacy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Asma Khurshid
- School of Pharmacy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Sarah Tessier
- School of Pharmacy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Marie Sicard
- School of Pharmacy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Alan J. Knox
- School of Clinical Sciences, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Linhua Pang
- School of Clinical Sciences, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Cornelia H. de Moor
- School of Pharmacy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
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Ugai H, Dobbins GC, Wang M, Le LP, Matthews DA, Curiel DT. Adenoviral protein V promotes a process of viral assembly through nucleophosmin 1. Virology 2012; 432:283-95. [PMID: 22717133 DOI: 10.1016/j.virol.2012.05.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 05/08/2012] [Accepted: 05/24/2012] [Indexed: 12/19/2022]
Abstract
Adenoviral infection induces nucleoplasmic redistribution of a nucleolar nucleophosmin 1/NPM1/B23.1. NPM1 is preferentially localized in the nucleoli of normal cells, whereas it is also present at the nuclear matrix in cancer cells. However, the biological roles of NPM1 during infection are unknown. Here, by analyzing a pV-deletion mutant, Ad5-dV/TSB, we demonstrate that pV promotes the NPM1 translocation from the nucleoli to the nucleoplasm in normal cells, and the NPM1 translocation is correlated with adenoviral replication. Lack of pV causes a dramatic reduction of adenoviral replication in normal cells, but not cancer cells, and Ad5-dV/TSB was defective in viral assembly in normal cells. NPM1 knockdown inhibits adenoviral replication, suggesting an involvement of NPM1 in adenoviral biology. Further, we show that NPM1 interacts with empty adenovirus particles which are an intermediate during virion maturation by immunoelectron microscopy. Collectively, these data implicate that pV participates in a process of viral assembly through NPM1.
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Affiliation(s)
- Hideyo Ugai
- Division of Human Gene Therapy, Departments of Medicine, Obstetrics and Gynecology, Pathology, and Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Soucek S, Corbett AH, Fasken MB. The long and the short of it: the role of the zinc finger polyadenosine RNA binding protein, Nab2, in control of poly(A) tail length. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1819:546-54. [PMID: 22484098 PMCID: PMC3345082 DOI: 10.1016/j.bbagrm.2012.03.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 03/01/2012] [Accepted: 03/02/2012] [Indexed: 11/23/2022]
Abstract
In eukaryotic cells, addition of poly(A) tails to transcripts by 3'-end processing/polyadenylation machinery is a critical step in gene expression. The length of the poly(A) tail influences the stability, nuclear export and translation of mRNA transcripts. Control of poly(A) tail length is thus an important mechanism to regulate the abundance and ultimate translation of transcripts. Understanding the global regulation of poly(A) tail length will require dissecting the contributions of enzymes, regulatory factors, and poly(A) binding proteins (Pabs) that all cooperate to regulate polyadenylation. A recent addition to the Pab family is the CCCH-type zinc finger class of Pabs that includes S. cerevisiae Nab2 and its human counterpart, ZC3H14. In S. cerevisiae, Nab2 is an essential nuclear Pab implicated in both poly(A) RNA export from the nucleus and control of poly(A) tail length. Consistent with an important role in regulation of poly(A) tail length, depletion of Nab2 from yeast cells results in hyperadenylation of poly(A) RNA. In this review, we focus on the role of Nab2 in poly(A) tail length control and speculate on potential mechanisms by which Nab2 could regulate poly(A) tail length based on reported physical and genetic interactions. We present models, illustrating how Nab2 could regulate poly(A) tail length by limiting polyadenylation and/or enhancing trimming. Given that mutation of the gene encoding the human Nab2 homologue, ZC3H14, causes a form of autosomal recessive intellectual disability, we also speculate on how mutations in a gene encoding a ubiquitously expressed Pab lead specifically to neurological defects. This article is part of a Special Issue entitled: Nuclear Transport and RNA Processing.
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Affiliation(s)
- Sharon Soucek
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Anita H. Corbett
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Milo B. Fasken
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
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Mankodi A, Wheeler TM, Shetty R, Salceies KM, Becher MW, Thornton CA. Progressive myopathy in an inducible mouse model of oculopharyngeal muscular dystrophy. Neurobiol Dis 2011; 45:539-46. [PMID: 21964252 DOI: 10.1016/j.nbd.2011.09.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 09/04/2011] [Accepted: 09/13/2011] [Indexed: 01/23/2023] Open
Abstract
The genetic basis of oculopharyngeal muscular dystrophy (OPMD) is a short expansion of a polyalanine tract (normal allele: 10 alanines, mutant allele: 11-17 alanines) in the nuclear polyadenylate binding protein PABPN1 which is essential for controlling poly(A) tail length in messenger RNA. Mutant PABPN1 forms nuclear inclusions in OPMD muscle. To investigate the pathogenic role of mutant PABPN1 in vivo, we generated a ligand-inducible transgenic mouse model by using the mifepristone-inducible gene expression system. Induction of ubiquitous expression of mutant PABPN1 resulted in skeletal and cardiac myopathy. Histological changes of degenerative myopathy were preceded by nuclear inclusions of insoluble PABPN1. Downregulation of mutant PABPN1 expression attenuated the myopathy and reduced the nuclear burden of insoluble PABPN1. These results support association between mutant PABPN1 accumulation and degenerative myopathy in mice. Resolution of myopathy in mice suggests that the disease process in OPMD patients may be treatable.
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Affiliation(s)
- Ami Mankodi
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14620, USA.
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